diff --git a/run_tests.sh b/run_tests.sh
index 264d3c04..004987c7 100755
--- a/run_tests.sh
+++ b/run_tests.sh
@@ -11,6 +11,7 @@ function usage {
   echo "  -s, --no-site-packages   Isolate the virtualenv from the global Python environment"
   echo "  -x, --stop               Stop running tests after the first error or failure."
   echo "  -f, --force              Force a clean re-build of the virtual environment. Useful when dependencies have been added."
+  echo "  -u, --update             Update the virtual environment with any newer package versions"
   echo "  -p, --pep8               Just run pep8"
   echo "  -P, --no-pep8            Don't run pep8"
   echo "  -c, --coverage           Generate coverage report"
@@ -31,6 +32,7 @@ function process_option {
     -N|--no-virtual-env) always_venv=0; never_venv=1;;
     -s|--no-site-packages) no_site_packages=1;;
     -f|--force) force=1;;
+    -u|--update) update=1;;
     -p|--pep8) just_pep8=1;;
     -P|--no-pep8) no_pep8=1;;
     -c|--coverage) coverage=1;;
@@ -54,6 +56,7 @@ just_pep8=0
 no_pep8=0
 coverage=0
 debug=0
+update=0
 
 LANG=en_US.UTF-8
 LANGUAGE=en_US:en
@@ -148,6 +151,10 @@ then
     echo "Cleaning virtualenv..."
     rm -rf ${venv}
   fi
+  if [ $update -eq 1 ]; then
+      echo "Updating virtualenv..."
+      python tools/install_venv.py
+  fi
   if [ -e ${venv} ]; then
     wrapper="${with_venv}"
   else